
1) Marring
Found on
https://www.crosswordclues.com/clue/impairing

• (p. pr. & vb. n.) of Impair
Found on
http://thinkexist.com/dictionary/meaning/impairing/

impair, impairing, impaired 1. To make or to cause to become worse; to diminish in ability, value, excellence, etc.; to weaken or to damage; such as, to impair one's health; to impair negotiations. 2. To grow or to become worse; to lessen. 3. Etymology: from about 1374, it was ampayre, apeyre, from Old French empeirier, from Vulgar Latin impejorar...
Found on
http://www.wordinfo.info/words/index/info/view_unit/1593/
No exact match found.